signing up to join an oath for a militia. Supporting Russians on the way in becoming members of their own armed militia units. ABC right there again tonight. Reporter: Fresh mounds of dirt reportedly land mines buried by Russian forces along the border of crimea to seal it off. That board blocked for the third day in the row to foreign observers. Pro-russian troops firing warning shots. Tension is rise with reports of Russian troop members growing. Today we saw a rare and daring protest in crimea's capitol by Ukrainians against Russia's occupation here. We love Russian people. We don't like Russian government. Reporter: That protest extending to the opening ceremony of the par olympics in sochi where in front of president Putin Ukraine only sent out the flag bearer in a show of defiance. Today Ukraine's first medallist dedicating her medal to a peaceful and dependent Ukraine. Secretary of state John Kerry spoke with his Russian counterpart. But so far all efforts to deescalate this crisis have failed. Now just one week before they hold a referendum to decide if it wants to be a part of Russia.

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